Laser welding technology for skin-stringer joints is widely used in aircraft manufacturing. Double-sided laser beam welding of skin-stringer joints is an approved method for producing defect-free welds. The main drawback for the use of single-sided welding method for T-joints is the occurrence of weld defects. In order to achieve dual-beam laser welded T-joint, a dual-beam laser welding platform based on multi-axis CNC machine is set up in this article. A novel control method of double-sided seam tracking and error compensation based on vision sensor is proposed. The result shows that the dual-beam laser welding system can achieve dynamic deviation compensation accurately in the double-sided welding process at a high speed.